1. Field of the Invention
The present invention relates to a method of diagnosing lower urinary tract diseases, in particular, interstitial cystitis.
2. Description of the Related Art
Lower urinary tract disorders are a generic name for lower urinary tract dysfunctions, and lower urinary tract symptoms, which are caused by lower urinary tract disorders, are classified roughly into three groups: urinary retention symptoms (such as pollakisuria and urinary urgency), urination symptoms (such as decreased urine flow and interrupted urine stream), and post-urination symptoms (such as residual urine feeling and drops after urination). The lower urinary tract symptoms include lower urinary tract pain such as micturition pain, bladder pain, and urethra pain; detrusor overactivity; and dysuria. Furthermore, hematuria is observed in some lower urinary tract disorders. The lower urinary tract disorders are caused by diseases such as interstitial cystitis, prostatic hypertrophy, prostatitis, prostadynia, bladder neck contracture, overactive bladder, and painful bladder syndromes.
Among them, interstitial cystitis causes symptoms such as pollakisuria, excessive urination, urinary urgency, bladder discomfort, and bladder pain and is an intractable disease, though urinary tract infection and other apparent pathosis are not observed. Interstitial cystitis is defined as a disease accompanying non-specific chronic inflammation of bladder, but the cause thereof is not yet clarified. Therefore, the disease is not clearly defined. In addition, interstitial cystitis cannot be cured by conventional antibiotic therapy, unlike common bacterial cystitis.
At present, NIDDK (National Institute of Diabetics and Digestive and Kidney Diseases) is most well known as a diagnosis standard of interstitial cystitis. Japanese Society for Scientific Research of Interstitial Cystitis has published “Interstitial Cystitis Diagnosis and Treatment Guideline” in 2007 and has indicated a clinical diagnosis standard.
In the above-mentioned diagnosis of interstitial cystitis, abnormalities of bladder surface (epithelium) are one of important grounds of the diagnosis. Therefore, it is necessary to observe (1) a bladder ulcer or (2) a petechial hemorrhage caused by bladder hydrodistention under anesthesia. The bladder ulcer is observed by cystoscopy, but only about 10 to 50% of ulcers can be found by conventional endoscopic findings of bladder using visible light (referred to, for example, Nigro, D. A., et al., Urology, 1997, 49 (Supplement 5A), pp. 86-92, and Waxman, J. A., et al., The Journal Of Urology, Vol. 160, November 1998, pp. 1663-1667). Such a low sensitivity is a large problem for the examination requiring a high sensitivity.
That is, in the conventional findings using visible light, only obvious ulcers such as Hunner's ulcer can be detected. Urologists may think ulcers as that bladder mucous membrane is merely red and may overlook many abnormalities. In other words, though an ulcer is aggregation of blood vessels newly formed in a surface of the bladder, conventional cystoscopy detects blood vessels newly formed in a surface and also blood vessels newly formed in a deep portion of the bladder as red images and cannot or hardly differentiate between the two.
In the diagnosis by bladder hydrodistention under anesthesia, a subject has to stay in a hospital and general anesthesia including lumbar spinal anesthesia is necessary for the hydrodistention. Furthermore, the subject has a pain after the treatment. Thus, physical, mental, and economic burdens of the subject are enormous. In addition, burdens of a person who conducts the diagnosis are similarly enormous and stressful.
Consequently, though a large number of people, particularly middle-aged women, suffer from symptoms of interstitial cystitis, many of them cannot receive diagnosis or are not correctly diagnosed. Consequently, they are still compelled to suffer from the symptoms.